5.4 File and Directory Protections

The setgid bit on a directory (in the group-execute portion represented as an s or S) forces all files to be created in the directory with the group of the parent directory rather then the user’s primary group. This is the BSD file creation semantics rather than SYSV.

By default Debian uses a umask of 755. It is a long and well known Linux tradition to create home directories world readable as it encourages a sharing environment. Users can always change the permissions on their home directory or any subdirectory they want to keep private.

To change this default behaviour edit /etc/adduser.conf to change the DIR_MODE option.

Your donation will support ongoing development and give you access to the PDF version of this book. Desktop Survival Guides include Data Science, GNU/Linux, and MLHub. Books available on Amazon include Data Mining with Rattle and Essentials of Data Science. Popular open source software includes rattle, wajig, and mlhub. Hosted by Togaware, a pioneer of free and open source software since 1984. Copyright © 1995-2021 Graham.Williams@togaware.com Creative Commons Attribution-ShareAlike 4.0.